Is this site and forum the correct place to ask DIY questions? I recently purchased a very used terramite T5C backhoe/loader. I want to install a geothermal heating/cooling system. From what I can tell so far, DX requires a smaller horizontal loop footprint and is more efficient than water. But, the coolant cost must be wildly expensive and a leak in a DX loop would require an expensive recharge upon repair. Although a water loop requires a larger footprint and is not quite as efficient, I believe it would be cheaper to maintain and repair. Do you believe this is a fair summary? I am planning to install loop field myself. I would like opinions on the pros and cons of the two types of systems and degree of difficulty of installation. Thank you!!! Tod

I rented a Terramite once. It was weak and slow. Doing a horizontal loopfield using it would have been Hades on earth.

Just my $0.02

Thanks for your .02 on the terramite, but it is that or a shovel :-) Do you have any experience with DX loops? Do you prefer the water loop?

Thanks,
Tod

Where are you located? How deep are horizontal loops in your area?

Your T5C can dig a maximum of 8'4". Digging that deep with it will have you sitting in one place for long periods of time. I have been digging a 640' long 30" deep trench with a similar sized Kubota. I have completed 480' in about 24 hours of digging. That is less than 30' per hour. If I were trying to dig an 8' deep horizontal loop I doubt I could dig 10' per hour. In fact I am sure that in most places I would hit rock that I could not dig at all.

I am installing a vertical loop system at my new house. I hired a well driller to install them. If I were going with horizontal loops I would have the JD 160 (40,000 pound) excavator that will be digging out the basement dig the loops.

My loops will be plain water. In Central Arkansas it does not get cold enough to freeze the water in the loop.

Not sure any DX system is available to DIY. Further the "smaller footprint" means less loop in the ground not less digging. Our slinkies in MI are about 110' long and need a 36" trench (600' of pipe) while our horizontal DX are 125' long and tubes must be 4' apart (250' pipe). Which takes less digging?
You need a partner design company. We help DIY's routinely.
Good Luck,
Joe

Happy to help fellow DIY'ers.
You may want to do some reading first though. If you can't answer +90% of your own questions from reading past posts and research, you are probably better off finding a contractor. I gotta warn you, it can be a lot more work than it looks like on paper.
Highly recommend this doc. http://www.geokiss.com/res-design/GSHPDesignRec2.pdf

I have no experience with DX so can't compare them with water looped systems.

What are the pros/cons of renting a larger chain trencher?

Please forgive my stupidity, but why does it matter how long it will take a DIYer that owns the backhoe to dig the tranches? I can understand someone in the business that longer dig times cost them more money to complete a job, or someone renting equipment that is paying by the day / hour is costing them more money every minute they keep the equipment, but a DIYer with there own equipment has all the time in the world.   

So it takes him a little longer to do the same job, so what.

A large trencher cuts and backfills incredibly fast even in clay, as long as you don't have tree roots or large field stone. If you have a clear and level field, even an amateur could finish in a day or two. Straight lines are easy, tight curves and sharp angle cuts are difficult even for an experienced operator to backfill, requiring a lot of shovel and rake work. If you're doing a two pipe installation, you'll probably need a few extra hands to pull pipe and backfill by hand(no fun).
If you are not real slick on a excavator, you could spend more in gas/diesel than the trencher rental would cost.

On the other hand, with a frontend loader you could do a slinky, requiring less field. It also could take a while, leaving you with an open pit for some time.(danger, liability).

If you are not experienced operator, either way, you are probably going to make a mess of your yard. Thats just the way it goes. You may want to dig a test pit, since you already have the backhoe. See what your soil is like six feet down, and get an idea of how your machine cuts.

Reading back, I realize, I may be a bit biased. The back and forth nature of backhoe work always did drive me crazy.

I have dug pits about 6’ deep to date, so far, the deeper I dig the easier it gets. No large rocks, shale, running water etc. Soil at that depth looks like moist sand impregnated clay. I bought the Terramite to avoid rental costs. I have efflorescence in a few places within my basement walls. So, I will be installing french drains around my foundation. I have dug up 3 of 7 tree stumps, and last but not least, I intend on digging the GEO loop. Then I will sell the backhoe, hopefully, close to my purchase price. Or that is my plan. I believe 6’ cover will be an acceptable trench depth here in central Virginia. (Still researching the numbers)

Well, there goes my percieved savings in trench effort. As for the design, I probably will do as you say.

I just wanted to thank you guys for taking the time to comment on this subject!

HMMMMM, I like the way you think.

That's an Excellent idea! Every few months where I live, there is a Lyons Heavy equipment auction. What the big contractors do is buy the equipment they require to do a job and auction it back off when it's completed. While it might seem like a lot of money to spend 60 to 80 thousand dollars on a backhoe, it's entirely possible to auction it off and actually turn a small profit on it.  Reselling at profit would greatly depend on the condition of the equipment and how much a demand there is at that particular time.  I guess in theory, if you could determine when contractors jobs slack off (I would assume in the winter) and when work picks up (again I assume spring or summer) you could buy low and sell high.  

It sounds like you have some nice dirt. I respect your willingness to work and hope you are able to complete the project.